Method of making hollow balls.



No. 736,229. PATENTED AUG. 11, 17903.

' 0. DAVIS.

METHOD OF MAKING HOLLOW BALLS. 7 APPLICATION FILED APR. 11. 1902. 80MODEL.

3mm addild 1762 4115,

:%W;'E T v I NITED STATES Patented August 11, 1903 ATENT FFICE.

CLELAND DAVIS, OF THE UNITED STATES NAVY, ASSIGNOR TO CAMBRIDGEMANUFACTURING, COMPANY, OF WILMINGTON, DELAWARE, A CORPO- RATION OFDELAWARE.

METHOD OF MAKING HOLLOW BALLS.

SPECIFICATION-forming part of Letters Patent No. 736,229, dated August11, 1903.

Application filed April 11, 1902.

T0 aZZ whom it may concern.-

Be it known that I, OLELAND DAVIS, lieu tenant United States Navy,acitizen of the United States,stationed atWashingtomin the District of:Columbia, have invented certain new and useful Improvements in Methodsof Making Hollow Balls, (Case E and I do hereby declare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

My invention relates to improvements in the method of making elasticballs.

The object of my invention is to provide a method for easily and quicklymaking hollow elastic balls, commonly intended to be used as golf-balls,although, of.course, said balls may be used for other purposes.

In the accompanying drawings,which ill ustrate the way in which theinvention is performed, Figure 1 representsa section through amoldcontaining the ball. Fig 2 is a section through a modified form of ballas made byI my method and illustrates the ball before the plug isinserted; and Figs. 3 and -l are ,isections of other forms of finishedball, the

/ ball shown in Fig. 3 being of the same construction as that shown inFig. 1.

The mold A is made of two separable members in the ordinary way.- Thematerial to be molded into the form of a hollow ball is placed in thespherical cavity A in the mold,

and inclosed in the center of the mass is an inflatable bagB, of rubber,gold-beaters skin, or other suitable material, which bag is providedwith a neck Z), through which water or other suitable fluid may beforced under pressure. Ordinarily I prefer to use an inelastic fluid,such as water, because a high pressure is more easily obtained. Theinner walls of the mold A may be indented, if desired, to formprojections 011 the ball such as are common in golf-balls. Various kindsof materials may be used in forming the shell of the ball. In Fig. 1 Ihave shown surrounding the inflatable bag B a hollow rubber core 0,which in turn is surrounded by a casing D, made of celluloid or somesimilar nitrocellulose compound. In the form shown in. Fig. 2

Serial No. 102,447. (No model.)

the ball consists of a single hollow shell of rubber, gutta-percha, ornitrocellulose com- 'passing outward through the tube 19. After the bagis filled with water and distended to the proper size it is placedwithin the mold A and the materialto be molded is placed around it. Ifdesired,the mold may be slightly heated. ater under pressure is thenforced into the bag 13 until the required pressure, which is somethingin the neighborhood of two thousand five hundred pounds, is produced,which pressure is sufficient to properly mold the ma terial, whethernitrocellulose, rubber, gutta percha, or other equivalent materials,into the desired shape and form. The ball is then removed from the moldand the water drained out. Air orother gas is then pumped in untilaconsiderable pressure is obtained within the bag B. The cork E is thendrawn up into the inner end of the tube 1), where it is firmly held bythe air-pressure. The ball is then removed from the mold and the tube 1)is either cut off, if it is made of metal, or else folded back withinthe opening 0, as shown in Figs. 3 and 4, and the plug F, of suitablematerial, is inserted. Then the outer part or shell of the ball is madeof a nitrocellulose compound,

this plug F may be made of the same compound and dipped in a suitablesolvent, the result being that when the plug F is placed in position theparts will mold themselves together. The final result is a hollowelastic low hemispheres or other spherical segments and the contiguousedges may be welded together by heating, by the use of a suitablesolvent, or in any other convenient way.

Having thus described my invention, what I claim, and desire to secureby Letters Patent of the United States, is

i 1. The method of making hollow elastic balls, which consists inforcing an inelastic fluid into a hollow inflatable bag until said baghas assumed the proper size and shape, placing around said bag thematerial to be molded, inserting said bag and said covering materialinto a mold, forcing an inelastic fluid into said bag under pressure,thereby causing the outer material to assume the proper size and shape,removing the inelastic fluid from said bag, forcing an elastic fluidinto said bag and finally sealing the orifice leading into saidinflatable bag.

2. The method of making hollow elastic balls, which consists in forcingan inelastic fluid into a hollow inflatable bag until the latter hasassumed the proper size and shape, placing around said bag the materialto be molded, heating a mold, inserting the bag and covering materialinto said mold, forcing an inelastic fluid under pressure into saidmold, thereby causing the covering material to be molded into the propersize andshape, removing said inelastic fluid from said bag, forcing anelastic fluid into said bag and finally elos ing the orifice throughwhich said fluids were forced into said bag, in such a way as to make ahomogeneous outside.

In testimony whereof I afflx my signature in presence of two witnesses.

CLELAND DAVIS.

W'itnesses: v

FRED W. ENGLERT, J. STEPHEN GIUsTA.

